GaryP65 Posted December 9, 2015 Share Posted December 9, 2015 (edited) I think I posted this before but age is getting to me.Having little experience with these tanks, I hooked up a clear line to see the action of the fuel being drawn into the unit.My question is:While cranking, I see the fuel going up the tube into the tank but once I stop cranking, the gas recedes back into the gas can. Is that normal?Mind you, one of the first things I did was to take it apart and inspect the inards. The float has no holes, the linings seem fine and the rest of the do-hickey's (flap, levers, etc..) are good too.So again, is that normal behavior? Edited December 9, 2015 by GaryP65 (see edit history) Link to comment Share on other sites More sharing options...
dl456 Posted December 9, 2015 Share Posted December 9, 2015 Gary ,Vacuum is required to hold the inner tank valve shut .If you are just cranking and not running the engine, gas will recede when the vacuum stops.Hope this helps.Dennis Link to comment Share on other sites More sharing options...
GaryP65 Posted December 9, 2015 Author Share Posted December 9, 2015 That makes sense. So then there should be enough gas left in the tank to start it next time without and issue?Of course depending on how long it sits.... correct? Link to comment Share on other sites More sharing options...
cahartley Posted December 9, 2015 Share Posted December 9, 2015 (edited) Yes Gary.For first time priming turn the engine over a bit leaving the throttle closed and choked for maximum vacuum.The tank will start filling remarkably fast....... In the event the tank would run empty from a leak or some such thing I fill the carburetor float chamber with gas and just start the engine. Edited December 12, 2015 by cahartley (see edit history) Link to comment Share on other sites More sharing options...
GaryP65 Posted December 12, 2015 Author Share Posted December 12, 2015 OK... Carb is plumbed and looking good. I did notice that I was getting gas in the vacuum line so I'm thinking there is something wrong in the tank.FYI. I took the plug out and it ran better which is why I took the tank apart. The float is good; no gas in it. the springs are OK, the guide on the bottom of the inner tank is secure and the flapper works so I looked to the head of the unit. Attached is a video that I hope the experts can help me on. Sorry for the shakiness of it. I'm no cinematographer File is too large to upload, click link to Dropboxhttps://www.dropbox.com/s/5i262b7lsua0vic/20151211_215209.mp4?dl=0 Link to comment Share on other sites More sharing options...
cahartley Posted December 12, 2015 Share Posted December 12, 2015 Your video is good as far as it goes but there are two valves.When one opens the other closes.You must lower and lift the float to check the operation of both. Give that a look >>> http://www.allpar.com/fix/fuel/vacuum-tank-fuel-pump.html Link to comment Share on other sites More sharing options...
22touring Posted December 12, 2015 Share Posted December 12, 2015 (edited) Gary, have you tried this yet? Hook up a vacuum pump, like a Mity-Vac or the equivalent, to your fuel line coming from your gas tank. Pump it up and see if fuel comes through. (Use the auxiliary in-line container for the fuel; don't let it get into the vacuum pump.) If no fuel comes up from the tank, then you have either a vacuum leak in the fuel line from the tank, or a blocked fuel line from the tank. If fuel does come through, note how much vacuum it takes to bring it up from the tank. Now connect your vacuum gauge to the inlet of the vacuum tank and see how much vacuum it produces. (You will have to run your engine from a separate fuel source when you do this, and remember that the vacuum tank won't produce any vacuum when it is already full.) Now compare the two figures. Edited December 12, 2015 by 22touring (see edit history) Link to comment Share on other sites More sharing options...
GaryP65 Posted December 12, 2015 Author Share Posted December 12, 2015 Your video is good as far as it goes but there are two valves.When one opens the other closes.You must lower and lift the float to check the operation of both. Give that a look >>> http://www.allpar.com/fix/fuel/vacuum-tank-fuel-pump.htmlThanks cahartley. Nice article. I've read that one some time ago, very helpful to a newbie.Maybe I should post a video showing the action on the valve as the float moves up and down. It looks to me as that is happening, the valve I pointed out moves up and down but doesn't 'close'. In my video, the other valve is closed I believe as it should.The point of all this is I would like a difinative answer on the problem of gas in the vacuum to manifold line.The mechanics manual states the probable causes but it looks like I pass all the issues and feel that it's something else, like the 'action' of the tank.22 touring, I get the concept but while it seems easy to the experienced, it is at the moment, pass my limited knowledge. I feel that the part about pulling the filler plug out and it running better is worth something. Also, I am not using the main tank yet. That's next after I get this sorted out.I'm so close to getting this girl running smoothly it's killing me!Anyone wants to call me, I'd love to chat917-831-0989.Sometimes easier than text/email. Link to comment Share on other sites More sharing options...
Grimy Posted December 12, 2015 Share Posted December 12, 2015 (edited) That the tank works better when the fill plug is removed leads me to believe that the atmospheric valve or the passage to the vent pipe is **partially** clogged. The two side-by-side valves in the pot metal "head" or cover are (1) the suction valve and (2) the atmospheric valve. They are connected by overcenter linkage and a pair of matched springs to ensure that when one valve is closed, the other is open. With the head off and the float dangling from it (head held in a vertical position), slowly work the float up and down and watch the valves open and close. the valves should open and close **sharply** and quickly. The valves are rather like small carb needle valves. They sometimes grow "whiskers" of corrosion, which can be cleaned with carb cleaner and a small NYLON (not metal) brush or toothbrush. Further, their seats are staked into the pot metal; those seats sometimes come loose. Re-staking without fracturing the pot metal can be difficult, so if a seat is loose or out of position, be very careful. Also check the pivot for the overcenter linkage for corrosion which might inhibit its smooth operation, and use the aerosol carb cleaner and nylon brush to clean the pivot as well. If the valves do NOT open and close sharply, the springs should be examined closely and possibly replaced. One of the first things to do is to remove the external vent pipe, spray carb cleaner from the outside in, then apply some shop air. Hopefully this will clear the partial blockage. Sometimes the replacement springs will be a little too tight and inhibit the overcenter linkage from operating by the minor force exerted by the rising and falling float. In such a case, stretch each spring just a little until the float moving up and down will trip the linkage reliably and sharply. Hope this helps! Edited December 12, 2015 by Grimy (see edit history) Link to comment Share on other sites More sharing options...
nearchoclatetown Posted December 12, 2015 Share Posted December 12, 2015 That the tank works better when the fill plug is removed leads me to believe that the atmospheric valve or the passage to the vent pipe is **partially** clogged. Or maybe the gasket or inner tank is blocking the vent hole. Link to comment Share on other sites More sharing options...
Grimy Posted December 12, 2015 Share Posted December 12, 2015 It certainly would be good to verify that the vent passage is not blocked by the gasket or by mis-alignment of the inner tank, but either would have probably blocked venting completely. Six months ago I had a blocked vent on a 1925 Pierce 80, and the carb cleaner + shop air solved that problem--but the diagnosis took longer... :-) Link to comment Share on other sites More sharing options...
GaryP65 Posted December 12, 2015 Author Share Posted December 12, 2015 I think I get the valve situation now. In looking at the drawing from the article from cahartley, I see the vent valve pulls DOWN to close. I see that one valve will always be either open or closed at some point depending on the position of the float. When I raise and lower the float, I get quick action on the valves.I'm gonna check blockage on both valves tomorrow along with inner tank and gasket alignment.Keep you posted. 1 Link to comment Share on other sites More sharing options...
cahartley Posted December 12, 2015 Share Posted December 12, 2015 Yes Gary........that's where the springs come in for over-centering the lever.Also check VERY closely to make sure the seats aren't the least bit loose in the housing.I fixed one in mine with a drop of loctite.......problem solved....... Link to comment Share on other sites More sharing options...
stakeside Posted December 14, 2015 Share Posted December 14, 2015 Curous if there is a certain vacuum requirement required from the engine for these tanks to operate correctly. If so what would be a good vacuum pressure at the engine? Link to comment Share on other sites More sharing options...
cahartley Posted December 14, 2015 Share Posted December 14, 2015 It takes very little vacuum to lift the gas from the tank.It's just that with the choke and throttle closed you get more of it. Link to comment Share on other sites More sharing options...
GaryP65 Posted December 15, 2015 Author Share Posted December 15, 2015 (edited) I removed all the fittings on the head and sprayed the hell out of it with carb cleaner. Poked a wire thru the hole on the rim where the vent tube is. Screen looked good. I see the seat on the valve in my video and it looked like it wasn't in all the way so I tapped it down and while not quite flush to the rest, it seemed to do the trick.Put it all together, primed it. Sucker started right up and I no longer see gas in the vacuum line! Edited December 15, 2015 by GaryP65 (see edit history) 1 Link to comment Share on other sites More sharing options...
cahartley Posted December 15, 2015 Share Posted December 15, 2015 Yup......those seats are fussy little things.They nearly drove me insane too until I accidently, on purpose sort of, saw what was happening!....... Link to comment Share on other sites More sharing options...
GaryP65 Posted December 15, 2015 Author Share Posted December 15, 2015 I'm slow but I'm coming around! 1 Link to comment Share on other sites More sharing options...
22touring Posted December 15, 2015 Share Posted December 15, 2015 I'm slow but I'm coming around!Gary, when I first got my car running I had a problem with the Stewart carb where the car would run initially but stall about a mile down the road, when I came to the first stop sign. The air valve had become detached from the metering rod, and since I didn't understand the Stewart's theory of operation, I didn't even know it was broken. Did you know that AAA will cancel your towing insurance after you have been towed 19 times? 1 Link to comment Share on other sites More sharing options...
GaryP65 Posted December 16, 2015 Author Share Posted December 16, 2015 how did you fix that? Link to comment Share on other sites More sharing options...
22touring Posted December 18, 2015 Share Posted December 18, 2015 I was able to silver solder them back together where they had been swaged. Link to comment Share on other sites More sharing options...
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